Dust control, as used herein, is defined as the prevention or reduction of the extent to which fine particulates become airborne or suspended in air. Dust is generated in significant quantities during the mining, handling, transportation, and storage of coal; dust is also generated during the processing, transportation and handling of rock, green and calcined petroleum coke, ores (for example iron ore), grains, limestone, gypsum, fly ash, cement clinker, bauxite and fertilizers (such as potash and phosphates), among others. Road dust also proves to be a problem.
Industrial sources of fugitive dust include open operations, leaks and spills, storage, disposal, transit or poor housekeeping of sundry finely divided solid particulates. The iron and steel industries are replete with examples of the above enumerated categories. Wind erosion of exposed masses of particulate matter such as coal or mine mill tailings, fertilizer, etc., causes both air pollution and economic waste. Detrimental effects on health and cleanliness result where these fine particles are carried aloft by the winds.
Hot substrates (&gt;120.degree. F.) pose a more difficult problem for controlling dust emissions than substrates at ambient temperatures. Water is typically used as the primary active and distribution medium for dust control at ambient temperatures. However, at elevated temperatures, water evaporates quickly, and loses effectiveness at controlling dust emissions.